K1=4.6e-7;
K2=4.7e-11;
Kw=1e-14;
kH=29.76; # atm/(mol/L)

P(h,L) = (kH*(h/K1))*(h+L-Kw/h)/(1+2.0*K2/h);

plot [5.5:10] P(10**(-x),1e-4),3.5e-4
